Gas-pump.



0. A. ANDERSON,

GAS PUMP.

APPLICATION FILED JUNE 9, 1909.

Patented 0st. 7, 1913 Im/n 0r MM GQIIorn CHARLES A. ANDERSON, OZF 'CHI'CKG'O, ILLINOIS.

GAS-PUMP.

Specification ofletterslatent.

Application filed-T111169, 11909. Serial No. 501,028.

T0 all whom it mag concern:

Be it known that I, GHA'RLES A. ANnEnsoN, a citizen of the United States, residing in the city of Chicago, county of 'Cook, and State of Illinois, have invented certain new and useful Improvements in Gas-Pumps, of which the following is a specification.

This invention relates to improvements in gas pumps and refers more particularly to a mechanically driven gas pump adapted to be used with a closed circulating system.

Among the salient objects of the present invention are to provide a-pump of the above character which operates to automatically draw in and compress-charges of :gas in each of two similarly constructed chambers, and to continuously circulate the compressed gas through the system; vto provide a construction in which the pressure of the gas upon the opposite sides of the piston is so balanced as to reduce to a minimum the working stress upon the actuating parts of the pump and thus materially increase the life and efficiency of the latter; to provide a construction in which certain of the actuating,v parts are seated in a closed gas containingchamber which is sealed against the escape of gas in a novel manner; to provide an improved constructionof the piston rods which permits the use of a unitary structure, and thus obviating the necessity of joints in the rod; to provide novel operative connections between the main drivingshaft and thewalking beam to which the piston rods are connected; to provide an apparatus which is especially suitable for embodiment in small sizes, so that it may 'be used for small refrigerating plants; and in general to provide a simple, efiicient and improved construction of. the character referred to.

The invention consists in the matters hereinafter described and inore particularly pointed 1 out in the appended claims. v

' In 'the-drawi-ngsaFigure 1 isa verticaljsece. tional view .-=rnyim med device Fig. 2 is v a similar sectional viewtaken. onlines of Fig. 1. Fig. 3 isia top planview of the device and showing more particularly the connections between the punrp and the external system. v

Referring to the drawings 1 designates as a whole the base casting which is provided centrally with a cylindric journal box or walking beam chamber 2 in which is mounted the walking beam 3 in the manner now .to

be described. One side of the walking beam seated an annular washer 10.

chamber is 'apertured to receive a journal block 4 which is screw threaded into the side wall of the base 'cas'ting as shown at 5; and

face of 'the journal block 4 is provided with an annularboss 9, and between this boss and the adjacent edge of the walking beam is This washer serves to prevent the escape of gas from the walking beam chamber 2 and accordingly means are provided for holding the washer in constant frictional engagement with the boss 9. To this end the annular socket member 7 is counter-bored at its inner face to receive the set screw 11 which extends through a stufling box chamber 12 fixed to the outer face of the end wall ofthe base casting. This stu-fiing box is provided with the usual packing 13 which is confined in position by 'means of a packing ring 14,

screw threaded into the stuffing box chamber 12 and apertured to receive the set screw 11.

The inner end of the" latter 'is slightlycounter sunk into the end of the rock shaft 6 as shown at 15 in order to permit the shaft abuts against the upper face of the base cast-' Within each of these cylinders 17 17 is seated a hollow elongated piston 18, 18' respectively. Each of these pistons communicates at its lower end with the walking beamchamber and is connected to the walking beam itself by means of an elongated piston rod 19. One end of each of these rods is screw threaded into the closed upper end of its piston as shown at 20, while the other end of the rod is similarly connected Patented@ct.7,1913.

I as shown at 21 to an arm 22 pivotally mounted on the adjacent end of thewalking beam. As a feature of the present invention in the upper end of each of these piston rods is interposed a flexible connection 23. This connection permits ..of the piston rod flexing slightly upon the oscillation of the walking beam, while it is at the same time sufficiently rigid to. withstand the thrusts of the piston. It will thus be seen that I obviate the necessity of having end joints in the piston rod as is usual in the present constructions.

It may be here stated that the walking beam is preferably immersed in oil, and in order to reduce the friction between the piston and the inner face of its cylinder, the former is provided at its lower end with annular grooves 24 which carry a portion of the oil into engagement with the inner face of the cylinder upon the upward stroke of the piston in an obvious manner. The oil may be admitted into the chamber through any suitable opening as shown at 25.

Describing now the manner of actuating the rock shaft and connected parts, to thatend of the former which extends through the journal box 4 is keyed acrank arm or lever 26 which is forked at its upper end as shown at 27 for a purpose hereinafter described. Within suitable bearing supports 28 mounted upon the upper face of the base casting is rotatably journaled the main driving shaft 29. One end of this shaft is provided with a combined driving pulley and fly wheel 30, while to the other end is sleeved an annular disk 31 carrying at its outer face a pin 32 and roller 33. This roller is adapted to ride within the forked extension of the crank arm 26, and as the drive shaft 29 is rotated the crank arm will be oscillated in an obvious manner. Inasmuch as this crank arm is operatively connected to the pistons in the manner hereinafter described it will be seen that the latter will be alternately reciprocateol inopposite directions,

In the present instance the pump is shown as connected to opposite sides of the closed system in such manner that each cylinder will alternately receive gas from the exhaust side of the system and force it into the high pressure side thereof. To this end a common inlet pipe 34 is connected to the upper end of each of the cylinders by means of branch pipes 35, 36 respectively. The high pressure side of the system is similarly connected to the upper end of the respective cylinders by means of a common outlet pipe 37 and branch pipes 38, 39 respectively. Within each of these branch pipes 35 and 36 is interposed an inwardlyopening check valve 40 while in each of the opposed branch pipes 38 and 39 is interposed an outwardly opening check valve 40'.

In practice the gas is delivered from the then high pressure side of the pump at approximately eight hundred pounds pressure and returned to the then intake side of the pump at approximately four hundred pounds pressure. These figures may of course be varied but I have found that in small refrigerating plants about the above pressure is required. It may be here stated that the pressure of the gas as it travels through the system is lowered by means of a reducing valve, not shown, or in any well known manner. While the rocking lever or walking beam operates in a substantially sealed chamber and the feed of the pistons is such that there is practically no leakage of gas from one cylinder to the other; nevertheless it is practically impossible to make a positively closed working joint, and accordingly the pressure in the walking beam chamber will usually be in the vicinity of the mean between the maximum and minimum pressures which obtain in the two gas cylinders. In-' asmuch as in the present instance this mean pressure is ap roximately six hundred pounds it may e assumed that the same pressure exists in the walkin beam chamber. In other words the difierences between the mean pressure and the maximum and minimum pressures in the two gas cylinders is reduced to approximately two hundred pounds, and accordingly the strain.

upon the actuating parts of the pump is reduced to a minimum.

Assuming that the piston 18 has started upon its upper stroke and the piston 18' in the opposite direction, the cylinder 17 will be forc ng gas into the high pressure side of the system while the opposite cylinder is taking in the gas from the low pressure side in the following manner: Gas at high pressure from the cylinder 17 will pass into the branch pipe 38 and through the check valve 40 into the "outlet pipe 37. At this time the pressure in the cylinder 17 will have fallen below the low pressure of the system whereupon the check valve 34 of the branch pi e 36will open and gas rush into the inlet side of the cylinder 17. At this time the outwardly opening check valve 40' will be closed for the reason that the pressure on the outer side of this valve will exceed the pressure in the cylinder 17'. In the same manner the inwardly opening check valve 40 of the branch pipe 35 will be closed for the reason that the pressure in the cylinder 17 exceeds the pressure in the intake pipe 34. When the pistons have reached the limit of their respective strokes and started in the opposite direction exactly the reverse conditions take place'when the pistons are reciprocatcd in the opposite direction. Inasmuch as the main shaft is being constantly driven it will be seen that the gas will be constantly circulated through the system.

While I have herein shown a preferred embodiment of my invention it may be more or less varied in details of Construction Without in any manner departing from the spirit of the invention.

I claim as my invention:

1. In a gas pump, the combination with a gas-tight walking beam chamber, of a pair of elongated gas cylinders mounted above said chamber, a hollow elongated piston in each of said cylinders, each of said pistons being of nearly the same length as the cylinders, sealed at their upper ends and open at their lower ends, a piston rod in each of, said pistons and extending into the walking-beam chamber, a rock shaft journaled in said latter chamber,.a walking-beam carried thereby and o eratively connected to each of said rods, a riving shaft, operative connection between the rock shaft and the driving shaft, means for supplying gas to and venting it from the respective cylinders at points above the upper ends of the pistons and from a source independent of the walking beam chamber, said parts being so arranged that the pressure above the pistons in each cylinder is alternately raised and lowered above a substantially constant pressure in the walking-beam chamber.

2. In a gas pump, the combination with a gas-tight walking-beam chamber, of a pair of relatively narrow elongated gas cylinders .mounted above said chamber, a piston in each of saidcylinders, each piston being of nearly the same length as its cylinder, sealed at its upper end and open at its lower end, a walking-beam mounted in said walking- 1 beam chamber, a piston rod for each piston,

said rods being of relatively small diameter, connected at one end to the walking-beam and also to the upper closed end of the respective pistons, the up er end of said rod having an integral flexible part to permit flexing of the rod upon the actuation of the walkingbeam, means for actuating said walking-beam, and means for admitting gas to the upper end .of each cylinder from a source in ependent of the walking-beam chamber, and means for venting gas from each cylinder.

3. In a gas pump, the combination with a gas-tight walking-beam chamber, of a pair of gas cylinders, a piston for each cylinder, a journal block seated in one side of said walking-beam chamber, a socket member formed at the opposite side of said chamber, a

rock shaft having one end engaging the socket member, and having its opposite end extending out through the journal block,ra walking-beam keyed to said rock shaft Within said chamber, a washer mounted on the rock shaft and interposed between the walkingbeam and the adjacent face of the journal block, means for maintaining a substantially uniform gas pressure within the Walkingbeam chamber, meansfor applying end pres- &

sure on said rock shaft tending to automatically force the washer into engagement with the journal block to prevent any leakage of gas through the journal block, and operative connections between the pistons and the ends of said Walking-beam.

4. In a gas pump, the combination with a gas-tight walking-beam chamber, of a pair of gas. cylinders mounted above said cham her, a piston in each of said cylinders, each of said pistons being sealed at the upper ends and open at their lower ends, a piston rod in each of said pistons, a walking-beam I mounted in said walking-beam chamber, op-

erative connections between the piston rods and the walking-beam, means for actuating said walking-beam, means for admitting gas at relatively low pressure to the respective cylinders at their upper ends from a source independent of the walking-beam chamber, and means for venting gas from the upper ends of the cylinders at relatively high pressure; there being at all times a substantially uniform pressure in the walking-beam chamber that is intermediate said low and high pressures.

5. In a gas pump, the combination with a gas-tight sealed chamber, having gas therein at substantially uniform pressure, of a pair of gas cylinders, pistons for each cylin der, an actuating member seated in said sealed chamber, operative connections between said actuating member and each piston, means for supplying gas at relatively low pressure to the upper end of each of said cylinders at points above the pistons, means for venting gas at relatively high pressure from each of said cylinders, the pressure on said sealed chamber being at all times intermediate said high and low pressure. c

' 6. In a gas chamber, the combination with a sealed chamber,-having gas therein under pressure, a pair of gas cylinders, a piston foreach'of said cylinders, an actuating member seated in the sealed-chamber,

-operative connections bet-ween each piston and actuating member, means for alternately supplying gas at relatively low pressure to each of said cylinders from a source independent of said sealed chamber, and venting it at high pressure from each of said cylinders, the pressure ,in said sealed chamber being intermediate said high and low pressures.

, 7. In a gas pump, the combination with a gas-tight walking-beam chamber, of a pair of relatively narrow elongated gas cylinders, hollow pistons in said cylinders, said pistons being open at their lower ends and closed at their upper ends, and of nearly the same length as the cylinders, a, walking-beam in said walking-beam chamber, a rock-shaft for said walking-beam, arms pivotally connected to theends of the walk- & 1,075,183

ing-beam, relatively small piston-rods co-nchamber, and means for venting gas at relanected to said arms and to the closed upper 'tively high pressure from said cylinders, ends of their respective pistons, each of said the gas pressure in the walking-beam chamrods having an integral flexible portion near ber being substantially uniform and inter- 5 its upper end to permit flexing of the rods mediate said high and low pressures.

as the vva1k1 ng-beam is actuated, means for CHARLES A. ANDERSON actuating said Walking-beam, means for admitting gas at relatively low pressure to the Witnesses: upper ends of the respective cylinders'from LOIS FORGE,

iii a source independent of the Walking-beam EMILIE ROSE. 

